Expression of c-myc proto oncogene is regulated by multiple mechanisms. Here, we report that the consensus of the regulatory region of interferondependent genes, GGAAAN1−3 GAAA, was found after computer search in the 5'-terminal flank of human c-myc gene in position (−76:−67). In vitro transcription of c-myc gene fragments showed that the consensus region competes with oligonucleotide GGGAAAATGAAACT for binding to specific protein(s). This oligonucleotide was shown to bind selectively the interferon-dependent positive transcription factor [1]. Transcription of c-myc fragments lacking 5'-terminal region up to positions −101 or +71 was initiated at two sites located in the first intron. These sites did not coincide with P1 in vivo RNA cap-site. Binding of the protein factor(s) to the regulatory region of c-myc gene −76:−67 blocked the in vitro transcription initiated in the first intron.
